yes, Azolla filiculoides. this name is recognised in PlantNet but other jurisdictions and NatureMapr have followed recent change and call it Azolla rubra. This needs a Ferns Moderator to verify it for you.
Thanks JaneR, I look forward to that. Getting across any identifications has been challenging enough for now; keeping up with the ongoing changes & refinements, is a new challenge I guess I'm about to embark on! I very much appreciate the benefits of your knowledge, thank you!